This sounds good. I assume that this is just for hole activation and
standard electroplating is done next to build up the holes. What is
the success rate at home? And estimated costs? I don't want to dive
into something that would be so hard to replicate. Thanks for the
Info Adam.
--- In Homebrew_PCBs@y..., Adam Seychell <adam_seychell@y...> wrote:
> The BLACKHOLE processes is fast, cheaper and safer to run than
conventional
> electroless copper. This is expected since its aim is to replace the
> electroless copper line in the PCB fabrication plant. The low
toxicity is the
> reason I choose to develop a carbon black processes myself at home.
However
> the chemistry of BLACKHOLE is a trade secret and your not going to
replicate
> the same results at home. BLACKHOLE SP is the latest process from
MacDermid
> and performs many times better than the process explained below. Of
course
> the hobbyist doesn't need the reliability of a multimillion dollar
plant
> producing a hundreds of panels a day. Its taken me about 6 months
of fiddling
> around with carbon black dispersions, conditioning solutions and
circuit
> board material to get a working process suitable for home use.
Basically my
> process can be written down as follows;
>
> 1) drill PCB
> 2) clean copper surface with week solution of detergent/NaOH and
600 emery
> paper.
> 3) rinse well with tap water
> 4) immerse in a "hole wall conditioner" 1 min
> 5) rinse well with with tap water
> 6) immerse in "carbon dispersion" 1 min
> 7) sponge off excess dispersion with sponge, so all holes are fully
empty.
> 8) hot air dry
> 9) repeat steps 4 to 8
> 10) immerse in "activator" for 1 minute
> 11) rinse well with with tap water
> 12) microetch in a conventional non-chloride etching solution
> 13) spray rinse with with tap water to remove all traces of carbon
on copper
> surface.
> 14) air dry (optional)
>
>
> Bath compositions/conditions;
>
> hole wall conditioner:
> 5 to 10 g/l gelatine
> 0.04 to 0.06 g/l CuSO4.5H20 (as a biocide)
> temperature between 26°C and 32°C
> agitation: unnecessary
>
>
> carbon dispersion:
> 2 to 4% (w/w) of non-ionic surfactant based
> conductive carbon black dispersion paste∗
> 6 to 10 g/l acetic acid
> room temperature
> agitation: unnecessary
>
>
> activator:
> 1 g/l of dye D&C Green No.5 , C.I 61570.
> room temperature
> agitation: not known
>
> non-chloride etchant:
> 100 to 200 g/l ammonium persulfate
> or
> 1% hydrogen peroxide
> 10% sulfuric acid.
> both baths may be used at room temperature.
>
>
> ∗ The carbon black dispersion paste is FLEXOBRITE BLACK 258/86
manufactured
> by Degussa Coatings & Colorants.
>
> You will have to phone around and get a 500g sample for aqueous
based
> non-ionic surfactant conductive carbon black dispersion. Many of
the colorant
> manufactures will have these. 500g will last you forever. There is
still a
> whole range of information I left out, either because I haven't
worked it out
> yet or I missed it. The D&C Green No5 is available from food, drug
& cosmetic
> dye suppliers, either as a sample or in small volume (1 kg). Good
luck
>
> Adam